Document 1 (JP 2003-69595 A) discloses an access control system. The access control system disclosed in Document 1 includes a home server connected to home devices via a home network. The home server includes an access control table, a user table, and a device table. Upon receiving a request of access from an external device to the home device, the homes server judges whether or not the requested access is permitted on the basis of the access control table, the user table, and the device table.
The access control system disclosed in Document 1 needs many pieces of information (authorization information) determining parameters for judging whether or not the access is permitted. Therefore, it is difficult and cumbersome for a user to create the authorization information with respect to a device which is newly added to the network.